Process of cracking oil



Sept..1,193l. s EGLOFF I PROCESS OF ICRACKIQNG OIL ori inal Filed Dec. 21, 1925 Patented Sept.- 1, 193i GUSTAV EGLOFF, OF CHICAGO, ILLINOIS, ASSIGNOR TO UNIVERSAL OIL PRODUCTS COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF SOUTH DAKOTA PROCESS OF CRACKING OIL Application filed December 21, 1925, Serial No. 76,638. Renewed september 2, 1930.

This invention relates to improvements in process of cracking oil, and refers more particularly to that type of process in which the oil is subjected to an initial heating, preferably in a suitable coil, and thence delivered to anexpansion chamber, the vapors removed therefrom subjected to suitable dephlegmation and the reflux preferably recracked.

The present invention is adapted to treat in one process various cuts of oil, each of which has a certain optimum conditioihof cracking which is different from that of the other cuts, and the present invention is adapted,'for example, to crack kerosene or kerosene and light gas oil, reflux condensate, fuel oil and residuum obtained from the cracking process itself. All these are preferably subjectcd to difie'rent conditions oftemperature' and pressure in the heating coil.

In order to more readily understand the invention I have shown the accompanying drawing, in which the single figure is a somewhat diagrammatic view, partly in side ele 'vation and partly in vertical section, of an apparatus suitable for carrying out the present invention.

Referring to the drawing 1 designates a furnace in which are mounted coils 2, 3, 4 and 5 adapted to respectively receive kerosene, reflux condensate, fuel oil and residuum. If desired the coils may be mounted in separate furnaces so asto more accurately control their temperatures. By havingthem in separate furnaces as stated, the temperature can be more accurately controlled. But for the purpose of illustration they are here shown in one. Kerosene or kerosene and gas oil,-or special distillate bottoms are fed to the coil 2 by means of the pump 6 and line 7 and delivered from the coil 2 to transfer line 8 having throttle valve 9 to the expansion chamber 10at a temperature of, say, 1000 deg. F., and a. pressure of 1200 pounds. Reflux i condensate is fed through line 11 and pump 12 to the inlet side of the coil 3, and delivered through transfer line 13 having throt-' tle valve 14 to the expansion chamber 10 at a temperature of, say, 900 degrees F., and a pressure of, say, 800 pounds. Fuel oil is delivered by means of pump 15 and feed line 16 to the fuel oil coil, and thence through transfer line 17 having throttle valve 18 to the expansion chamber 10 at a temperature of, say, 850 deg. F., and a pressure of, say, 300 pounds. The residuum is delivered by means of line 19 and pump 20 to the inlet side of the coil. 5, and then through transfer line 21 having throttle valve 22 to the expansion chamber 10 at a temperature of, say, 800 deg. F., and a pressure of, say, 250 pounds. This expansion chamber'lO may be insulated or it may be independently heated.

Vapors pass out of the top of expansion chamber through vapor pipe 23 having throttle valve 24 to theside of a dephlegmator 25. The top of the dephlegmator 25 is connected by vapor pipe 26 having throttle valve 27 to condenser coil 28, thence to the top of receiver 29. pipe 30 controlled by throttle valve 31, and liquid draw-off pipe 32 controlled by valve 33. The lower end of the dephlegmator is connected by line 34 to the line 11.

If desired, more or less of any of the cuts, of oil, including the residuum and the reflux condensate, may be bypassed out of the system through the bypass pipes 35, 36, 37, 38 and 39 through the control of suitable valves 40 and 41.

In carrying out the process, the various cuts of oil, including the reflux and residuum, are heated to the temperatures and subjected to the pressures heretofore described, and are delivered to the expansion chamber 10.

They may all be delivered at different points in the expansion chamber or more or less adj acent to the same points. As the various cuts enter the expansion chamber 10 the temperatures of the various cuts ivill be equalized, thus the highest temperature cut tending to facilitate the vaporization of the lower cuts which are at a less elevated temperature. The temperature of the dephlegmator 25 This receiver 29 has gas outlet may be controlled by any one of the methods now well known to those skilled in the art. The temperature of the vapors leaving the top of the expansion chamber may be, say, 900 deg. F., but this temperature, of course, may be varied, as may be the temperature at which the various cuts enter the expansion tially reduced chamber, as well as the pressure at which the cuts enter such expansion chamber.

That part of the system beginning with the expansion chamber, and including the dephlegmator, water condenser and receiver, may be operated under a pressure substanover'the pressure at which the various cuts of oil enter the expansion chamber, the pressure on this part of the system being reduced'to, say, 250 pounds and t e dephlegmator may, if desired, have a lower pressure than the expansion chamber. It is, however, desirable in this invention that the expansion chamber be maintained at a pressure substantially above atmospheric pressure, but somewhat lower than the pressure in the heating coil. Such reduction in pressure, of course, tends to flash the oil as it enters the expansion chamber and further facilitates distillation.

I claim as my invention: W

1. A process for cracking petroleum oil, consisting in independently heating under pressure charging stock, and residuum and reflux condensate obtained from the cracking of such charging stock, the various cuts above mentione each being heated separately and to different degrees of temperature, passing "such heated cuts under pressure to a suitable expansion chamber where the temperature is equalized, and drawing efi vapors therefrom, subjecting them to reflux condensing action, and subjecting the reflux condensate to the initial heating'treatment above referred to,likewise drawing off residuum from the expansion chamber and subjectin it to the initial heating treatment above re erred to, and maintainin a pres: sure on the various cuts of oil in t e initial heating zone.

2. A claim'according to claim 1 further characterized in that the oil in the expansion chamber is maintained under superatmospheric pressure, but lower than the pressure maintamed on the charging oil in the initial heating treatment.

GUSTAV EGLOFF. 

